1. Field of the Invention
The present invention relates to heating oil compositions for use in firing boilers or other heating units that must meet strict guidelines for emissions to the atmosphere, due to environmental concerns.
2. Description of the Related Art
The present invention provides a heating oil suitable for, inter alia, large boilers. These boilers may be used by manufacturers such as, for example, pharmaceutical manufacturers. Many petroleum-based heating oil mixtures have been used in the past, but they do not meet the requirements of the desired combination of adequate heating value, low sulfur emissions and economy. Such mixtures have been used as either fuel additives, or they have some combination of properties that does not meet environmental guidelines while being an economic fuel. These products are often a blend of various petroleum fractions, often designed to be a blend that reduces viscosity. Furthermore, some existing products are designed to reduce the amount of pollution thereby helping the environment, but at great expense.
One example of a fuel additive is U.S. Pat. No. 5,203,878 (No. '878) issued to Woomer et al. Similar to the present invention, this additive helps reduce pollutants to the environment. Additives are not used independently. They must be blended with fuel mixtures to achieve their goals. Indeed, the No. '878 patent achieves its goal by creating an additive. To be useful, that additive must be mixed with residual oils. The present invention, on the other hand, does not need to be blended with other fuels. Instead, it is used as a heating oil composition.
Another patent, U.S. Pat. No. 4,299,594, issued to Pelrine et al., discloses waste oils as a cutter stock to reduce the viscosity of oils. That invention employs waste oils in such a manner to reduce the need for valuable kerosene and gas oils. However, unlike the present invention, that patent does not use waste oils to lower the sulfur content. Furthermore, the No. '878 patent leads to the emission of other contaminants, such as lead, which need to be reduced in order to protect the environment.
Unlike the present invention, the prior compositions typically require either blending the product with a primary material to produce a heating oil, or they are merely additives to be mixed with fuels to achieve desired characteristics. Furthermore, the prior art does not address the specific objectives of this invention.
The present invention has several objectives. First, this invention provides a product with a sulfur content below 0.6% by weight to help reduce the amount of undesirable environmental emissions. At the same time, the invention permits a high enough level of sulfur to remain economically inexpensive to produce.
Accordingly, a second object of the present invention is to produce a heating oil more cheaply than the existing heating oils to result in less cost for operating boilers. Such economic efficiency may result in reduced expense of production for the consumers of the heating oil. This additional objective is assisted by yet another objective.
Another objective of the present invention is to maintain a high heating value. This high heating value may result in less fuel being required to operate a boiler. With less heating oil being required to operate a boiler, the boiler may operate at a lower expense. Accordingly, this objective of the present invention assists the second objective of reducing operating expenses of boilers.
The heating oil of the present invention is compatible with high sulfur diesel oil (0.5% sulfur content by weight). Therefore, this heating oil may be used as an alternative fuel.
Finally, an additional benefit of the present invention is maintenance of superior quality like that of clean prime products. Because of the high quality of the heating oil, the product of the present invention does not have to be mixed with other oils to achieve its objectives.